Typically, most people match the stair rod with the actual carpet runner and not the spindles. If you take a look at the image in the below link you'll see that this person has wroght iron spindles but is using an antique brass stair rod which highlights the gold tones in the runner:

However I have seen a few cases where the stair rod hardware does match the spindles, it's really a personal preference but typically you would choose your stair rod finish based on your runner colors.

This space is an example of symmetrical balance. The symmetrical balance in this room is seen in the spiral staircases and the arch leading into the other room. Symmetrical balance creates a restful and peaceful sensation and is easily perceived and appreciated.

Curved Line
This is an example of curved line for many reasons. The obvious location of the curved line is in both of the staircases. It's also in the table in the rug in between, which kind of ties it all together. There is also curves in the railings of the stairs. The curved staircases make this space more graceful and delicate.